Augmented reality includes a live view of a real-world environment that is augmented by computer generated sensory input(s), such as GPS graphics, video, sound, data statistics, and so forth. In contrast to virtual reality, which replaces the real-world environment with a simulated one, augmented reality elements are often displayed in real time in semantic context with elements of the real-world environment. For example, sports scores can be displayed on a television during a basketball game on a same screen. Head-mounted displays can also be used to place the virtual images over a view of the physical world such that both are in the user's field of view.